1. Field of the Invention
This invention a method to process hybrid circuits according to the so-called green-tape technology and also a device that employs the method, as set forth in the respective main claims.
The method according to the invention can also be employed for the processing of solar cells, printed circuits and anything else which can be used with the same system.
2. Discussion of Prior Art
The hybrid circuits of the so-called green-tape technology consist of very thin foils of alumina in the raw state or another analogous or like material, the foils having a circuit printed on one or both of their two faces.
The green-tape foils are superimposed on each other in a coordinated manner in a number which may even amount to various tens of foils, and the foils are then compressed so as to be bonded to each other and to produce a multi-layer element of a slender thickness.
The various components forming the green-tape circuit and included on the individual foils are possibly set in communication with each other by means of suitable holes made in the foils and filled with a conductive material.
The green-tape foils of the present technology are conveyed on supports, of paper for instance, to the various processes.
Paper supports are used advantageously to facilitate separation of the green-tape foils, since during the filling of the connecting micro-holes with the conductive material, that conductive material may emerge and become spread on and/or adhere to the support.
Lastly, the green-tape foils are dried, assembled in a pre-set number and compressed so as to obtain a multi-layer electrical circuit.
The operations of engaging, positioning and inserting the green-tape foils are carried out by hand and involve considerable times and costs as well as a great number of rejects owing to the lack of accuracy in the filling and printing operations (by screen process printing, for instance) and to the damage caused by manual handling.